An important tool for mitigating climate change may lie beneath our feet—soil management could increase our ability to keep carbon out of the atmosphere, a new study shows.
A paper published last week in the journal Scientific Reports estimates that by altering land use practices, the top layer of soil around the globe could increase the amount of carbon stored anywhere from 0.9 to 1.85 billion metric tons per year—an amount that equals the transportation sector’s carbon emissions.
Worldwide, scientists estimate that the earth’s soil contains about 2.5 trillion tons of carbon in its top three-foot layer. Agricultural activity, depending on the type, could release large amounts of carbon by disturbing the soil. Almost 50 percent of all potentially vegetated land surface has been converted to croplands, pastures, and rangelands. This, in turn, has contributed approximately 136 petagrams of carbon to the atmosphere since the industrial revolution. For comparison, fossil fuel combustion has pumped an estimated 270 petagrams of carbon into the atmosphere, according to the study.
The good news is this study shows how land management practices are an opportunity to reverse that trend. Rotating crops, composting, zero tillage, cover cropping and agroforestry can increase soil’s potential to keep carbon out of the atmosphere.
Despite this, soil management as a climate mitigation tool did not make it onto the official Bonn climate conference agenda, although it has been discussed in side events run by environmental groups.
Improving food security, increasing crop yields and increasing the resilience of agriculture to the effects of climate change are the main discussion points among policymakers. However, they tend to ignore the importance of land use management and what it can do to mitigate climate change.